<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
  <h1>注册页面</h1>
  <input type="text" placeholder="请输入用户名" @blur="f()" v-model="user.username">{{info}}<br>
  <input type="text" placeholder="请输入密码" v-model="user.password"><br>
  <input type="text" placeholder="请输入昵称" v-model="user.nickname"><br>
  <input type="button" value="注册" @click="reg()">

</div>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<script src="https://cdn.bootcdn.net/ajax/libs/axios/0.21.1/axios.min.js"></script>
<script>
  let v=new Vue({
    el:"body>div",
    data:{

        user:{
          username:"",
          password:"",
          nickname:""
        },
        info:""
    },
    methods:{
        reg(){

        },
      f(){
          axios.get("/check?username="+v.user.username)
              .then(function (response) {
                //alert(response.data);
                v.info=response.data;
              })
          console.log("用户名:"+v.user.username);
      }

    }
  })
</script>
</body>
</html>